Improvement in automatic telegraphs



T. A. EDISON. AUTOMATIC TELEGRAPH.

No. 195,751, Patented 0ct.2,l87'7 (Mmtmu Wad) 6% m W M9 N,PETERS.FHOTO-LITHOGRAPHER. WASHINGTON. D C

UNITED STATES PATENT QFFICE.

THOMAS A. EDISON, OF NEWARK, NEW JERSEY, ASSIGNOR TO HIMSELF AND GEORGEHARRINGTON, OF WASHINGTON, DISTRICT OF COLUMBIA.

IMPROVEMENT IN AUTOMATIC TELEGRAPHS.

Specification forming part of Letters Patent No. 195,751, dated October2, 1877; application filed January 27, 1875.

To all whom it may concern:

Be it known that I, THOMAS A. EDIsoN, of Newark, in the county of Essexand State of New Jersey, have invented an Improvement in AutomaticTelegraphs, of which the following is a specification:

This invention is forv bringing into operation condensers by alternatelyconnecting and disconnecting them from the line by revolvin g wheelshaving alternate conducting and non-conducting surfaces.

In the accompanying diagram the improve ment is illustrated.

At the sending-instrument the battery is divided, the part a beingconnected to the stylus b, and the part c to the stylus d and e, andthese are so arranged for the purpose of weakening the middle portion ofthe dash, because the stylus 11 drops into the large perforations for adash near the edge of that perforation, and remains a less time than thestylus d, and at that time throws into action a local circuit from thesmaller battery a, that is opposed to that of the main battery 0, andthus lessens the current in the middle of each dash-mark.

X is an ordinary branch circuit at the sendin g end for the staticdischarge from the line.

K K are signaling Morse relays used along the line. The helices of theserelays are not to exceed one inch in length, and the coils are shuntedwith a resistance equal, or nearly so, to the resistance of the coils onsaid relays, so as to provide a route for the induction set up in thecoils to circulate without going out upon the line to mutilate thesignals.

The natural effect of this induction-current wires 8 and 9 with thecondensers 0 G The springs 5 and 6 are connected with the line, and 7and 4 to the receiving-instrument 1'.

The condensers C C are, by preference, condensers in air withoutintermediate sheets of paper.

The Wheels f g, in the act of rotating, connect the condenser U in thecircuit of the line at the same moment that the condenser U is connectedto the receiving-instrument. This is then disconnected and connected tothe line, and 0 connected to the instrument.

In alternately throwing these condensers, first on the line and then onthe chemical receiving-instrument, with great rapidity, sig nals made onthe line at the distant station charge these condensers, and thecondensers transfer these charges to the receiver Without it having anyconnection whatewr with the line.

As the condensers can be made to hold these charges for a length oftime, it follows that by this method currents sent on one line may betransferred by condensers into another line, or to a short circuitcontaining a' chemical receiving-instrument. By this means the staticeffects are nearly overcome, and perfect signals are recorded.

I do not wish to confine myself to any particular mechanism foroperating the condensers; but

I claim as my invention- 1. The method herein specified of transferringthe signals of one electric circuit into another circuit by revolvingcircuit closing Wheels with conducting and non-conductin g surfaces andconnections to condensers and to the chemical recording-instrument,substantially as set forth.

2. The transmitting instrument provided with a circuit-closing point andopposing battery for lessening the battery-power in the middle portionof the pulsation for a dash, as set forth.

Signed by me this 18th day of January, A.

THOS. A. EDISON. Witnesses:

Gno. T. PINCKNEY, CHAS. H. SMITH.

